The S*** is about to hit the fan!!

The Amazon Basin is experiencing the the worst drought in 40 years. It is some thing that we all should be very worried about. For starters there is no El Niño signiture present. If it was then we certainly wouldn't be having the record breaking hurricane season we are currently having.

Could this be a consequence of climate change? If it is then we all should be very worried. Droughts in the Amazon would mean that the vegetation would die off releasing greenhouse gases and setting off a chain reaction that would lead to irreversable effects on the climate. The big question is have we crossed the threshold for a run away global warming? If that is the case then reducing carbon emissions may not have any effect. The drought is thought to be caused by warm sea surface temperatures in the Atlantic. This is also the cause of the hyperactive hurricane season that we have been having.

Some info can be found about the effects of drought in the Amazon in this paper. The paper is titled "Amazon drought and its implications for forest
flammability and tree growth: a basin-wide analysis" I haven't read through the paper properly just yet as I have more important things to do, however I will get around to it and give a synopsis of what I think.

Matt

 

Well, I'm not sure I see the connection between el Nino in the Pacific and Atlantic/Carribian tropical storms. Most of those storms, at least the weather pattern, develops over by northern Africa. And the Atlantic has, just in the last few years, moved into a new cycle, where there's going to be more storms...has to do with ocean currents and warmer waters, I don't really know a lot about it. This means we'll be having high numbers of tropical storms/hurricanes for anywhere from 10-20 years, till this cycle ends. Of course everything is connected, but still, el Nino doesn't happen every year...are you sure the two are connected that closely?

Besides, the shit is already hitting the fan, and has been for some time. But I'll check that paper out.

 

El Niño has a negative impact on tropical cyclogenisis. In an El Niño year there are fewer hurricanes in the atlantic basin. The movement of warmer water over the pacific and more importantly the movement of the storm cells that go with it disrupt the trade wind patterns in the atlantic. As a result there is more vertical wind shear which means any storm development in the atlantic is limited because the energy gets disapated over a larger area. There are 5 key ingredients for a hurricane to develop.
1. Low wind shear
2. Unstable atmospheric conditions.
3. Warm sea surface temperatures >27 deg C
4. Positive vorticity. Usually an existing disturbance for instance a tropical wave.
5. Strong enough force induced by the corriolis effect. This is why hurricanes never develop closer than 5degs from the equator.

If all five conditions are met then the atmosphere is said to be favorable for tropical cyclogenisis.

TrippinBTM you seemed to of miss read the point of my post. The post was about the drought conditions in the Amazon basin at the moment. The drought in the Amazon usually occurs when the El Niño signiture is present. At the moment it isn't. This is very unusual and should concern everybody. Having had a brief scan through the paper it goes on about how the drought conditions can affect plant growth and plant flamability. A major forest fire in the amazon would be everybodys worst nightmare. The Amazon is usually considered a carbon sink. If the drought conditions continue then the Amazon rainforest will cause a significant rise in the concentration of carbon dioxide in the atmosphere. This could have a knock on effect like a row of dominos on the release of other greenhouse gases into the atmosphere from other carbon sinks.

Going back to your post TrippinBTM the atlantic does seem to be going into an active phase. What causes it is subject to many debates and scientists are still not sure about it. There needs to be a lot of research done on it. El Niño does have an effect on the development of hurricanes for the reasons I have mentioned. As with anything in atmospheric sciences there are a lot of things we do not understand yet.

Matt

 

Today the climatologists at the Snow and Ice Data Centre in Colorado will publish the results of the latest satellite survey of Arctic sea ice(1). It looks as if this month’s coverage will be the lowest ever recorded. The Arctic, they warn, could already have reached tipping point: the moment beyond which the warming becomes irreversible(2). As ice disappears, the surface of the sea becomes darker, absorbing more heat. Less ice forms, so the sea becomes darker still, and so it goes on.

Last month, New Scientist reported that something similar is happening in Siberia. For the first time on record, the permafrost of western Siberia is melting(3). As it does so, it releases the methane stored in the peat. Methane has 20 times the greenhouse warming effect of carbon dioxide. The more gas the peat releases, the warmer the world becomes, and the more the permafrost melts.

Two weeks ago, scientists at Cranfield University discovered that the soils in the UK have been losing the carbon they contain: as temperatures rise, the decomposition of organic matter accelarates, which causes more warming, which causes more decomposition. Already the soil in this country has released enough carbon dioxide to counteract the emissions cuts we have made since 1990(4).

These are examples of positive feedback: self-reinforcing effects which, once started, are hard to stop. They are kicking in long before they were supposed to. The intergovernmental panel on climate change, which predicts how far the world’s temperature is likely to rise, hasn’t yet had time to include them in its calculations. The current forecast – of 1.4 to 5.8 degrees this century – is almost certainly too low.
http://www.monbiot.com/archives/2005/09/20/a-world-turned-upside-down/

Add that to your list of worries. And the guy who wrote has tons of other great articles, real smart guy.

 

That's true, about the permafrost. See, there's a LOT of dead plant matter frozen in that soil. If all the permafrost melted (unlikely but possible), and all that stuff decayed, we'd literally double the amount of carbon in the atmosphere. To say nothing of the methane.